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Showing posts from October, 2019

Content-Security-Policy and third party JS, a Threat Model view, PART 1

A lot has been done to defeat XSS and other potential vulnerabilities in nowadays frameworks (contextual encoding in React Angular... etc)  and development practices, still, XSS, and in general the ability for an attacker to execute arbitrary code (mostly Javascript) is still in the OWASP TOP 10 and at the root of many cybersecurity incidents. As mobile applications also became a wrap on top of a browser-based web application, the attack surface for XSS and other related malicious code injection widens even more. Given the situation leveraging browser mechanisms to restrict the Javascript code that the client can execute to only the expected one sounds like a great solution. Content-Security-Policy (some of the advanced features) has this potentiality but is mostly unused. I saw two main reasons for this: The advantage is hard to defend: 1) It needs to be fully understood, it needs clear evidence and arguments to justify it (that's why I'm writing this article). 2) It is